UPDATE - Which Jaguar motors have "valley pipes"?
Quick “Valley Pipe” Clarification (5.0 AJ133)

I’d been struggling to reconcile a lot of the online posts and advice about “valley pipes” on the XK100 and X150 with what I’m seeing in the factory documentation, so I did a deeper dive.

For the AJ133 5.0 NA, here’s what’s actually there:
• Front of engine: Outlet Tube
• Rigid, externally mounted
• Located forward in the valley between the cylinder heads
• Rear of engine: Crossover Pipe
• Routes coolant across the back of the engine near the firewall
• Not a valley component
• (Aftermarket replacement shown in the image)
• Throttle Body Heater Inlet Hose - Goes from the Swirl Pot to the Throttle Body on the 5.0's

The term “valley pipe” generally applies to earlier Jaguar V8s (notably the 4.0 / 4.2 supercharged engines) that used rubber coolant hoses routed under the intake in the V. That architecture does not exist on the 5.0.
The AJ133 5.0 NA has an “Outlet Tube” in front and a “Crossover Pipe” in the rear and the Throttle Body Inlet Heater Hose.

A lot of aftermarket listings call the front outlet a “Y-pipe,” which adds to the confusion.
Comments which follow we posted before this clarification.

(Thank you for your encouragement and support!)

Outlet and Crossover and Throttle Heat Tubes - 5.0L AJ133

 

does anyone make metal versions of these?

 

also what preventative maintenance is recommended on the 5.0na motors ?

 

Yes - I fact the Aftermarket Crossover Pipe is metal.

 

FWIW,
Be aware, three are varying qualities of the metal version. Also, I think JLR provides an option now too.
There are a number of conversations about this in the Land Rover forums.

Some are commenting about premature coolant system failures. I wonder if there is a relationship with the fluid change schedule.
At 100,000 km I did all of the "rubber" bits on most of the systems (including cooling). And preparing for the next major service at 200,000.

 

[QUOTE=guy;2894184]FWIW,
Be aware, three are varying qualities of the metal version. Also, I think JLR provides an option now too.
There are a number of conversations about this in the Land Rover forums.

Some are commenting about premature coolant system failures. I wonder if there is a relationship with the fluid change schedule.
At 100,000 km I did all of the "rubber" bits on most of the systems (including cooling). And preparing for the next major service at 200,000.[/QUOT


do you know the exact part number for the metal parts for the na 5.0?

 

Shortly after I bought my XK, in August, it developed a coolant leak. The car had approx 92k. The dealer (LR Scarborough) was cool enough to replace it, and did so with part #LR018275. The car had pretty extensive service history with no mention of that part ever having been replaced. If the first lasted 92k, I'm fine with a factory plastic part. A lot of those cheap aftermarket parts look like castings of castings.

 

The simple truth is that heat and time are the primary causes of deterioration of rubber and plastic parts. There is a lot of fiberglass filled nylon under the bonnet and some of it is baking for hours at over 200 degrees, which is where PA12 starts to become brittle. Rubber sufferes from heat soaking also. The Jaguar factory service guidelines took this into account, but some items, like this throttle heater inlet pipe are buried deep. I suspect the 60,000 mile 7 year rule applies to more than just fluid changes (spark plugs and transmission fluid). If you assume a 10,000 mile per year schedule, by year 7 you are out of warranty and with the shift to all electric, those of us who love these older cars are going to have to learn some new skills to keep our vehicles running.

 

David - Thank you for posting that. LR018275 appears to be the Land Rover number four the Throttle Body Heater Hose on the Range Rover and Rover Sport with the 5.0 Liter Supercharged motor. (AJ133SC) The part description feels like its "close enough in horseshoes and hand-grenades".

 

Juliam - From what Ive seen the only metal parts are aftermarket, not OEM.
Since the AJ133 is also in Land Rover's there could be cross overs there also.

 

I can verify there are aluminum valley pipes for the V6 (used in XF, LRs etc) and the Supercharged V8. NOT for the NA V8.
On the other hand, if you budget $1200 for Coolant Pipes, Hoses, Thermostat & Water Pump overhaul every 50k miles or 10 years, and pay attention on overheating (several obd2 tools), you won’t have surprises.

 

If there hasn't been aluminum pipes (Jaguar OEM) for the 5.0 N/A after all this time, now that the car has really aged, the chances of them becoming available are pretty slim. It seems that the plastic pipes (while they are still available from Jaguar) will be the only way to go for the 2010-2015 XK 5.0 N/A and all similar Jaguar models.

 

Do what I did on my drag car.... Braided stainless steel teflon with AN fittings. Yeah, it takes some work and a bunch of parts, bit it will not go BLOOEY for a hundred years.

 

I bet that would result in one shiny snake and custom one off flanges.
I think it would make more sense to buy a new plastic unit, dip it in multiple coats of plastic dip...






https://www.usplastic.com/catalog/it...AaAugnEALw_wcB





and then drain the coolant, change to CeeJays favorite water free version.
This would probably out live all of us!
wj

 

Yes in 2025 or so JLR went back and released the pipes in Aluminum! Surprised that happened. Still not a lot of information about them but we have seen a few pictures.




They do have Jaguar branding cast into them.





But there is some part number differences that have never been explained either.





And with the level of counterfeit parts in 2026 we have to be cautious that these might be as well.

That 5.0L NA does not have many aftermarket parts. Just a small production run I guess so low demand.
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